grpc/grpc-go · warning

conflicting global rules found

Error message

conflicting global rules found

What it means

Returned by logger.setDefaultMethodLogger when l.config.All is already non-nil (binarylog.go:114-115). The binary log filter config string contains two global ('*') rules. The first '*' sets l.config.All; the second finds it already set and rejects the duplicate. This error propagates through NewLoggerFromConfigString, which logs a warning and returns nil (disabling all binary logging).

Source

Thrown at internal/binarylog/binarylog.go:115

type logger struct {
	config LoggerConfig
}

// NewLoggerFromConfig builds a logger with the given LoggerConfig.
func NewLoggerFromConfig(config LoggerConfig) Logger {
	return &logger{config: config}
}

// newEmptyLogger creates an empty logger. The map fields need to be filled in
// using the set* functions.
func newEmptyLogger() *logger {
	return &logger{}
}

// Set method logger for "*".
func (l *logger) setDefaultMethodLogger(ml *MethodLoggerConfig) error {
	if l.config.All != nil {
		return fmt.Errorf("conflicting global rules found")
	}
	l.config.All = ml
	return nil
}

// Set method logger for "service/*".
//
// New MethodLogger with same service overrides the old one.
func (l *logger) setServiceMethodLogger(service string, ml *MethodLoggerConfig) error {
	if _, ok := l.config.Services[service]; ok {
		return fmt.Errorf("conflicting service rules for service %v found", service)
	}
	if l.config.Services == nil {
		l.config.Services = make(map[string]*MethodLoggerConfig)
	}
	l.config.Services[service] = ml
	return nil
}

View on GitHub (pinned to 0c51461d27)

Solutions

1. Remove the duplicate '*' entry from the GRPC_BINARY_LOG_FILTER value
2. Use only one global rule: '*' or '*{h:256;m:512}'
3. Validate the config string by splitting on commas and checking for duplicate '*' entries before setting the env var

Example fix

# before (duplicate global rule)
export GRPC_BINARY_LOG_FILTER="*,*"

# after (single global rule)
export GRPC_BINARY_LOG_FILTER="*"

// Validate the GRPC_BINARY_LOG_FILTER string for duplicate global rules
func validateBinaryLogConfig(s string) error {
    if s == "" {
        return nil
    }
    globalCount := 0
    for _, part := range strings.Split(s, ",") {
        if strings.HasPrefix(part, "*") {
            globalCount++
        }
    }
    if globalCount > 1 {
        return fmt.Errorf("duplicate global '*' rule in config")
    }
    return nil
}

When it happens

Trigger: Setting GRPC_BINARY_LOG_FILTER to a string containing two global rules, e.g., '*,*' or '*{h:256},*{m:512}'. fillMethodLoggerWithConfigString processes each comma-separated entry; the second '*' triggers setDefaultMethodLogger which finds All already set.

Common situations: Accidentally duplicating the global rule when editing the GRPC_BINARY_LOG_FILTER environment variable. Copy-pasting a config that already contained '*'.

Related errors

• conflicting service rules for service %v found
• conflicting blacklist rules for method %v found
• conflicting method rules for method %v found
• invalid config: %q, %v
• invalid config: %v

AI-assisted analysis of grpc/grpc-go@0c51461d27 (2026-08-11). Data as JSON: /api/errors/3ef380a2a739e9d4. Report an issue: GitHub.